The present invention relates to a system for indicating status of a vehicle.
There is today a growing awareness of safety risks when using vehicles. For example, many different constructions regarding vehicle alarms are known. Most of these systems generate a warning signal at the time of for example a burglary with the purpose of drawing attention to the vehicle and thereby scare off a burglar, or notifying an alarm central directly, e.g. over a cellular network. However, most of those systems are only effective for a short time after the burglary, and does not give notice to the vehicle owner or user. This may enable a burglar to hide in or around a vehicle and thereby the vehicle user is put in a dangerous position if he approaches the vehicle, not knowing about the burglary.
Further, many other potentially dangerous, harmful or inexpedient situations may occur in and around a vehicle. For example, a burglar may have stolen gasoline from the vehicle, soiling the surrounding area, or a dog may have been left in a vehicle, that is too hot, risking the health of the dog.
The object of the present invention is therefore to provide a system for alerting a user of a vehicle about potentially dangerous, harmful or inexpedient situations as he approaches or leaves the vehicle or, alternatively, exits or enters the vehicle.
A further object of the invention is to provide a flexible system that may be used in numerous different applications.
These and other objects are achieved by a system for indicating status of a vehicle, said system comprising a monitoring unit, positioned within the vehicle, comprising a first memory circuit connected with a first transceiver, said monitoring unit being arranged to monitor a selected set of parameters in the vehicle, whereby the current status of each parameter in said set of parameters is detected and stored in said first memory circuit; and a portable fob unit having a second transceiver; said transceivers being arranged to establish a short-distance wireless communication link between said fob unit and monitoring unit when within a communication range from each other, said system further comprising a register arranged to store a preferred or pre-set status of each parameter in said set of parameters, and a comparator, wherein the comparator is arranged to compare the contents of said first memory unit and the register, and output an alert signal if the status of any parameter in the monitored set of parameters differs from its preferred or pre-set status as stored in said register, said alert signal being transmittable to an alert device in said fob unit. With a system in accordance with the invention it is possible to check the status of a number of parameters in the vehicle from a distance, when approaching or leaving the vehicle. For example, an alert signal may be transmitted to the alert device if a vehicle door has been broken open or a window has been smashed during the time when the user has been away from the vehicle, thereby giving the user the possibility of being extra cautious when approaching the vehicle. When leaving the vehicle the system may be used to alert a user if for example a dog or baby has been left in the car of if a vehicle door is open.
Preferably, the comparator is arranged to compare the contents of said first memory unit and the register when receiving a trigger signal generated in a trigger device. By letting the comparison be trigged by a trigger signal instead of be executed constantly, computational power may be saved.
In accordance with a preferred embodiment of the invention, said trigger signal is arranged to be generated in said trigger device when a locking or unlocking signal is transmitted from the fob unit to the vehicle, to lock/unlock at least one vehicle door. Thereby, said status poll is done automatically when the user locks or unlocks the vehicle. The locking/unlocking signal device is further commonly integrated with a fob unit, resulting in the possibility for one unit for unlocking/locking and status poll of a vehicle. Further, by connecting the status poll to the locking and unlocking of the car, alteration information reaches the user at a time when he is much interested in this information, namely when approaching or leaving the vehicle.
In accordance with a second embodiment of the invention, said trigger signal is arranged to be generated in said trigger device when an enter or exit signal, indicating that the fob unit is moved between a position inside the vehicle and a position outside a vehicle, reaches said trigger device. In this case the fob may include a transponder, and the vehicle may include a system for tracking the fob in order to determine whether the fob is positioned in or outside the vehicle body. Such a system may be referred to as a passive entry system, and will not be described in closer detail herein. However, this construction enables said status poll to be done automatically when the user/fob exits or enters the vehicle.
Preferably, said register and said comparator is located in said monitoring unit, and said alert signal is arranged to be transferred over said communication link to said fob unit. With this construction, placing most major components of the system in the monitoring unit, the portable fob unit may be made smaller, and since only the alert signal, and not the entire content of the first memory circuit, is transmitted to the fob, the transmission may be very fast.
Further said alert signal suitably comprises a difference identity signal, unique for essentially each possible parameter difference, making identification of an occurred alteration of a vehicle parameter possible in said fob. Thereby, by including decoding information in the fob, full information regarding parameter alterations in the vehicle may be accessed from the fob, without transmitting the entire content of the first memory circuit to the fob.
Preferably, said alert device comprises a display for displaying information regarding parameter differences. This information may be taken from the second register or more or less directly from the communication channel. The display enables a user to access information regarding at least parameter alterations in the vehicle.
Suitably, the fob unit further comprises a second memory circuit, whereby the parameters stored in the first memory circuit are arranged to be transmitted over said communication link to said second memory circuit, when the alert signal has been sent to the fob unit, at least in a case when a locking signal or an exit signal has been transmitted to the vehicle from the fob unit. This enables a user to have access to the status of vehicle parameters, as they were when the user locked and left the vehicle or exited the vehicle. This status information may for example by displayed on demand on the display described above. Thereby a user may gain information for example regarding the current gasoline level of the vehicle when away from the vehicle.
Preferably, said monitoring unit is connected with at least one vehicle data network, such as a controller area network, within said vehicle. Thereby the monitoring unit may easily access a large number of electrically controlled features within the vehicle. Furthermore, said monitoring unit suitably comprises a programmable selector, for selecting parameters from said vehicle data network. This programmable means gives the system manufacturer and/or the system user the possibility to choose what parameters should be polled or detected and when the system should send an alert to the user about an uncertain condition.
Finally, at least one parameter stored in said first register having a changeable preferred or pre-set status, such as the gasoline level of the vehicle, is preferably arranged to be automatically updated with the current status as stored in the first memory circuit, when an alert signal has been transmitted. By updating the status of changeable parameters in the register each time an alert signal has been transmitted brings the system up to date. For example, if gasoline has been stolen from the vehicle, this is first reported to the user by means of the alert signal, and thereafter the new gasoline level is recorded in the register of preferred or pre-set statuses.